DE19505784A1 - Process for the preparation of electrophotographically active titanyl phthalocyanine - Google Patents

Abstract

The invention concerns a novel process for producing electrophotographically active titanylphthalocyanine. According to the previous process, titanylphthalocyanine in its active form IV, for example, is produced by dissolution in trifluoroacetic acid and methylene chloride and subsequent precipitation with a mixture of methanol and water. In the novel process, which has improved space-time yield, titanylphthalocyanine is dissolved in pentafluoropropionic acid and a solvent of the group comprising halogenated alkanes/aromatic compounds or halogenated alkanes/aromatic compounds and sulphonic acids. The active form is precipitated by precipitation with water in the presence of a further polar organic solvent. A mixture of pentafluoropropionic acid and methylene chloride and a mixture of p-toluene sulphonic acid and methane sulphonic acid are particularly suitable as solvents. The precipitated product displays very good electrophotographic properties.

Description

The invention relates to a new method of manufacture development of titanyl phthalocyanine modifications. This highly active In electrophotography, ven forms can be used as imaging Component are used.

The use of titanyl phthalocyanine in electrophotography Graphics has been known for a long time (e.g. US 3825422). At dealing with this connection has emerged represents that the electrophotographic activity of their Mor phology depends. The different modifications were made designated differently by the individual manufacturers. [Form I (or β or A), Form II (or α or B), Form III (or C or m), Form IV (or y or "new type"), Form X, Form Z1 and Form Z2]. It is important that the electrophoto graphically less active forms (e.g. the α or the β form) through appropriate treatment in electrophotographically more active Forms (preferably in Form IV) can be converted nen. As is known, this has been possible for a long time Known acid pasting happen in which a phthalocyanine in concentrated sulfuric acid and by adding what it fails again. It is difficult to understand the ver to obtain various modifications in pure form. On Process for the production of Form IV is for example in  DE 38 23 363 has been described.

For the production of titanyl phthalocyanine in general seems obviously the way out of diiminoisoindolenine and Ti (OR) ₄ (R = C₁-C₆) to be more advantageous than from phthalodini tril and titanyl chloride. The Her is described in detail different polymorphic forms of titanyl phthalocyanine in EP-A-460565 and additional applications therefor. The manufacturer Form IV is made from crude titanyl phthalocyanine with trifluoroacetic acid / methylene chloride as solvent and subsequent precipitation of the titanyl phthalocyanine with a Solvent system, especially an alcohol (MeOH) and Water. The precipitate is then washed and dried. In the additional patent (EP-A- 508772), Form I from 1,3-diiminoisoindolenine is disclosed and to produce titanium tetrabutoxide, these in trifluoroacetic acid dissolve acid to form Form X and Form X by treatment with halobenzene, especially chlorobenzene, in to convert form IV.

According to Fujimaki, Y., essential features of Form IV are et al., J.Imag.Techn. 17 (1991) 202 a dark fall of 13 V / sec (charging potential -600 V), a half-fall energy E / 2 of 0.75 erg / cm² (at 800 mm) and a residual potential at 10 erg / cm² of 70 V. Form IV is still characteristic X-ray diffraction peaks at 2θ at 9.4 ° and 27.3 °.

The invention has for its object a new Ver drive to the production of electrophotographically active Tita To provide nylphthalocyanine.

According to the invention, the process for the production of electrophotographically active titanyl phthalocyanine in that raw, electrophotographically inactive titanyl phthalocyanine in a mixture of pentafluoropropionic acid and a solution agents from the group halogenated alkanes, halogenated aromatics or halogenated alkanes and / or halogenated aromatics and Dissolves sulfonic acids or mixtures of sulfonic acids, and the titanyl phthalocyanine with water, optionally in the presence of a precipitates another polar organic solvent.  

In the electrophotographically active Tita produced nylphthalocyanine is obviously one of type IV, since its characteristic features in the X-ray has a diffraction pattern, d. H. in the X-ray diffraction pattern it shows characteristic diffraction angles at 9.4 ° and 27.3 °.

The halo used in the method according to the invention Generated alkane is a polychloro or polybromoalkane, preferably wise selected from methylene chloride, dichloroethane, tri chloromethane, trichloroethane, especially methylene chloride. On Halogenated aromatics used are, for example, chlorobene Zen.

The also as a solvent in combination with a halogenated alkane and / or halogenated aromatics used The sulfonic acid is an aliphatic or an aromatic one Sulfonic acid, especially a fluorinated sulfonic acid. It In addition to monosulfonic acids, disulfonic acids, carboxy sulfonic acids, sulfophosphonic acids are used. Especially advantageous sulfonic acids are selected from p-toluenesul fonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, before preferably p-toluenesulfonic acid or methanesulfonic acid or a Mixture of these two. However, other sulfonic acids can also be used rainy can be used.

The ratio of pentafluoropropionic acid to halogenated tem alkane / aromatics to sulfonic acid or sulfonic acid mixture is in the range from 1: 2 to 6: 0.1 to 4, preferably in Range from 1: 2.5 to 4.5: 1 to 2.5.

Titanyl is preferably used as the starting product phthalocyanine made from diiminoisoindolenine.

The precipitation of the solution described in the above tel (mixed) dissolved titanyl phthalocyanine can in water done, but is preferably with a mixture of Me thanol: water carried out, the proportion of methanol in the Range is 40 to 60%, especially in the range of 45 to 55%, preferably the ratio is 1: 1.

Compared to the previous activation process with Tri fluoroacetic acid and methylene chloride show the present  Process a much better space-time yield, esp especially when with pentafluoropropionic acid, methylene chloride and a mixture of methanesulfonic acid and toluenesulfonic acid is worked. It can also be used as a raw material less pure titanyl phthalocyanine can be used, whereby there are economic advantages.

Surprisingly, especially in relation to the Presentation in EP-A-460565 that

• 1) the solution in another solvent system possible is and
• 2) the precipitation with the solvent system methyl alcohol / water in the specified mixing ratio 60 : 40 to 40: 60 does not lead to type X (see table 2 and in particular table 3 in EP-A-460565), but to type IV.

If only water is used for the precipitation, a high proportion is obtained Type IV received.

The invention will be explained in more detail by examples the.

Example 1

10 g of titanyl phthalocyanine were mixed in a mixture of 60 ml of pentafluoropropionic acid (PFPS) and 240 ml of methylene chloride (MeCl) solved. The dark green solution became good in 1.5 l poured stirred mixture of methanol and water (1: 1). When the precipitation was complete, the mixture was over a glass frit filtered. Subsequent washing with water (four times with 1 l) followed by washing with MeCl (0.5 l) and acetone (0.5 L) and drying in vacuo gave 9.9 g of deep blue tita nylphthalocyanine with the electrophotographic properties, which are listed in Table 1.

Example 2

10 g of titanyl phthalocyanine were mixed in a mixture of 15 ml of PFPS and 60 ml of MeCl and 75 ml of a 30% solution of p- Toluene sulfonic acid dissolved in chlorobenzene. The dark green lion solution was in 2 l of a well stirred mixture of methanol and water (1: 1) poured. When the precipitation was finished the mixture is filtered through a glass frit. The following  Washing in the same manner as in Example 1 gave a deep blue Titanyl phthalocyanine with the elec photographic properties.

Example 3

10 g of titanyl phthalocyanine were dissolved in a mixture of 15 ml PFPS, 60 ml MeCl and 20 ml methanesulfonic acid. The dark green solution was poured into 1.5 l of a well stirred mixture of methanol and water (1: 1). When the precipitation was complete, the mixture was filtered through a glass frit. The subsequent washing in the same way as in Example 1 and drying in vacuo gave 4.9 g of a deep blue titanyl phthalocyanine with the electrophotographic properties listed in Table 1.

Example 4

The procedure was as in Example 3, but the precipitation with a mixture of methanol: water of 60:40. To filtering, washing and drying were obtained deep blue titanyl phthalocyanine with the desired electrofo graphic properties as in example 3.

Example 5

The procedure was as in Example 3, with the exception of the sen that a mixture of tri fluoromethanesulfonic acid and toluenesulfonic acid in the ratio 1: 2 and in an amount of 15 ml. After this Filtration, washing and drying were obtained deeply blue titanyl phthalocyanine with the desired electrophoto graphic properties as in example 3.

The electrophotographic properties of the after Titanylphthalocyanine produced by various processes were determined in a double-layer system. In addition, a aluminized polyester base with a dispersion of Titanyl phthalocyanine in polycarbonate / methylene chloride layers. The CGL so produced after drying was with a solution of N, N'-diphenyl-N, N'-di- (m-tolyl) benzidine coated in polycarbonate / methylene chloride and after measured after drying.  

Table 1

Mean in it
U _D = dark waste
U₀ = charging potential
E _0.5 = the amount of light necessary to reduce U₀ to 50%
U _R = residual potential with 6 µJcm ^-2 white light

The products produced according to Example 1 or 2 or 3 show the X-ray diffraction spectra according to FIG. 1 or FIG. 2 or FIG. 3.

Claims (8)

1. A process for the preparation of electrophotographically active titanyl phthalocyanine, characterized in that titanyl phthalocyanine is dissolved in a mixture of pentafluoropropionic acid and a solvent from the group consisting of ( 1 ) halogenated alkanes, ( 2 ) halogenated aromatics and ( 3 ) a combination of halogenated alkanes and / or halogenated aromatics and sulfonic acids or sulfonic acid mixtures, and the titanyl phthalocyanine precipitates with water, optionally in the presence of a further polar organic solvent. 2. The method according to claim 1, characterized in that the halogenated alkane is selected from methylene chloride, Di chloroethane, trichloromethane and trichloroethane, and it preferred is methylene chloride. 3. The method according to claim 1, characterized in that the Sulfonic acid is an aliphatic sulfonic acid under methanesulfonic acid, trifluoromethanesulfonic acid. 4. The method according to claim 1, characterized in that the Sulfonic acid is an aromatic sulfonic acid selected from Benzenesulfonic acid, p-toluenesulfonic acid, 1-naphthalenesulfonic acid re, 2-naphthalenesulfonic acid, especially p-toluenesulfonic acid is. 5. The method according to claim 1, characterized in that the Sulfonic acid is a mixture of 2 or more sulfonic acids, preferably a mixture of p-toluenesulfonic acid and methane sulfonic acid.   6. The method according to claim 1, characterized in that the Precipitation with a mixture of polar organic solvent / - Water takes place. 7. The method according to claim 6, characterized in that the Precipitation with a methanol / water mixture in the range of 40 up to 60% by volume of methanol, preferably in the range of 45 up to 55% by volume of methanol, especially in a ratio of 1: 1. 8. The method according to claim 1, characterized in that the Titanylphthalocyanin used from Diiminoisoindolenin forth is posed.